Introduction
Clinical laboratory testing is essential for disease diagnosis, treatment monitoring, and health assessment. UV-Vis spectrophotometry is one of the most commonly used quantitative techniques in hospital laboratories and independent clinical testing centers. Numerous clinical biochemical parameters are determined through spectrophotometric methods, including liver function, kidney function, blood glucose, lipid profile, and cardiac enzyme markers.
The core detection principle of automated clinical chemistry analyzers is based on UV-Vis spectrophotometry. STON Technologies' NanoQuant series spectrophotometers serve as valuable tools in clinical diagnostics for kit development, method validation, and small-batch testing.
Liver Function Tests
- ALT: NADH consumption monitored at 340nm (rate method)
- AST: NADH consumption monitored at 340nm (rate method)
- Total Bilirubin (TBIL): Diazo method at 540nm
- Total Protein (TP): Biuret method at 540nm
- Albumin (ALB): Bromocresol green method at 640nm
Kidney Function Tests
- BUN: Urease-GLDH method at 340nm
- Creatinine (Cr): Jaffe method (alkaline picrate) at 505nm
- Uric Acid (UA): Uricase-peroxidase method at 546nm
Blood Glucose and Lipid Profile
Glucose (GLU):
The glucose oxidase-peroxidase (GOD-POD) method is the most common approach. Glucose generates hydrogen peroxide under GOD catalysis, which reacts with phenol and 4-aminoantipyrine via peroxidase to form a red quinoneimine dye measured at 505nm.
Lipid Profile:
- Total Cholesterol (TC): Cholesterol oxidase method at 505nm
- Triglycerides (TG): GPO-POD method at 505nm
- HDL-C: Direct method at 600nm
- LDL-C: Direct method at 600nm
Cardiac Enzyme Panel
- Creatine Kinase (CK): NADPH rate method at 340nm
- Lactate Dehydrogenase (LDH): NADH rate method at 340nm
- HBDH: NADH rate method at 340nm
Cardiac enzyme testing is critical for early diagnosis of acute myocardial infarction and evaluation of thrombolytic therapy.
Therapeutic Drug Monitoring
Drugs with narrow therapeutic windows require blood concentration monitoring. UV-Vis spectrophotometry enables detection of:
- Theophylline: Bronchodilator, absorption at 275nm
- Phenytoin: Antiepileptic, absorption at 247nm
- Acetaminophen: Analgesic, absorption at 257nm
The NanoQuant1920 double-beam spectrophotometer with baseline flatness of ±0.0005A effectively subtracts serum matrix background absorption, improving accuracy.
Clinical Diagnostic Kit Applications
Many diagnostic kits rely on spectrophotometric principles. In kit development and QC, the NanoQuant series is used for:
- Standard curve establishment and validation
- Lot-to-lot variability assessment
- Accelerated stability study monitoring
- Method comparison studies
Advantages in Clinical Testing
- Photometric Accuracy: ±0.002A for reliable enzyme activity results
- Stable Optical System: Double-beam design eliminates source drift for kinetic monitoring
- GLP Self-Verification: On-demand performance verification meeting QC requirements
- Data Management: USB/Email/PDF output for convenient test data archiving
Conclusion
UV-Vis spectrophotometry is indispensable in clinical laboratory testing. STON NanoQuant series spectrophotometers provide accurate, stable, and reliable performance as valuable tools in clinical diagnostics.
